That sticky window could be letting hundreds of dollars a year blow right out as you climate-control the whole block. You could shrink your power bill by dropping $500 on a professional energy audit, or you could do it yourself with Black & Decker’s TLD100 laser pyrometer. No, it doesn’t glow orange, but it does have a brilliantly simple user interface that shows you exactly where that air is escaping. Power up and aim the pistol-shaped money-finder at the wall, where you’ll see a green dot of light that shows it’s calibrated to the mercury level at that spot. Move the laser around the room, and when the temperature shifts, the light changes to red (hotter) or blue (colder). When you’re done greening up your home, the TLD100 is still handy to have around. It’ll measure temperatures of -22 to 302 degrees Fahrenheit — so you can make sure that the hot tub is primed and the beer is cold enough to dull the pain of the massive to-do list you just developed.